its diminution in power, 1035. ——­, ——­ from adhesion of fluid, 1003, 1136. ——­, ——­ ——­ peculiar state of metal, 1040. ——­, ——­ ——­ exhaustion of charge, 1042. ——­, ——­ ——­ irregularity of plates, 1045, 1146. ——­, use of metallic contact in, 893, 896. ——­, electrolytes essential to it, 921. ——­, ——­, why, 858, 923. ——­, state of metal and electrolyte before contact, 916. ——­, conspiring action of associated affinities, 989. ——­, purity of its zinc, 1144. ——­, use of amalgamated zinc in, 999. ——­, plates, their number, 1151. ——­, ——­ size, 1154. ——­, ——­ vicinity, 1148. ——­, ——­ immersion, 1150. ——­, ——­ relative age, 1146. ——­, ——­ foulness, 1145. ——­, excited by acid, 880, 926, 1137. ——­, ——­ alkali, 931, 934, 941. ——­, ——­ sulphuretted solutions, 943. ——­, the acid, its use, 925, ——­, acid for, 1128, 1137. ——­, nitric acid best for, 1137. ——­, construction of, 989, 1001, 1121. ——­, with numerous alternations, 989. ——­, Hare’s, 1123. ——­, general remarks on, 1031. 1136. ——­, simultaneous decompositions with, 1156. ——­, practical results with, 1136. ——­, improved, 1001, 1006, 1120. ——­, ——­, its construction, 1124. ——­, ——­, power, 1125, 1128. ——­, ——­, advantages, 1132. ——­, ——­, disadvantages, 1132.  Batteries, voltaic, compared, 1126.  Becquerel, his important secondary results, 745, 784.  Berzelius, his view of combustion, 870, 959.  Biot’s theory of electro-chemical decomposition, 486.  Bismuth, its relation to magneto-electric induction, 139. Bodies classed in relation to the electric current, 823. ——­ classed in relation to magnetism, 255.  Bodies electrolyzable, 824.  Bonijol decomposed substances by atmospheric electricity, 336.  Boracic acid a bad conductor, 408. Brush, electric, 1425. ——­, produced, 1425. ——­, not affected by nature of conductors, 1454, 1473. ——­, is affected by the dielectrics, 1455, 1463, 1475. ——­, not dependent on current of air, 1440. ——­, proves molecular action of dielectric, 1449, 1450. ——­, its analysis, 1427, 1433. ——­, nature, 1434, 1441, 1447. ——­, form, 1428, 1449, 1451. ——­, ramifications, 1439. ——­ ——­, their coalescence, 1453. ——­, sound, 1426, 1431. ——­, requisite intensity for, 1446. ——­ has sensible duration, 1437. ——­ is intermitting, 1427, 1431, 1451. ——­, light of, 1444, 1445, 1451. ——­, ——­, in different gases, 1446, 1454. ——­, dark? 1444, 1552. ——­, passes into spark, 1448. ——­, spark and glow relation of, 1533, 1539, 1542. ——­, in gases, 1454, 1463, 1476. ——­, oxygen, 1457, 1476. ——­, nitrogen, 1458, 1476. ——­, hydrogen, 1459, 1476. ——­, coal-gas, 1460, 1476. ——­, carbonic acid gas, 1461, 1476. ——­, muriatic acid gas, 1462, 1476. ——­, rare air, 1451, 1455, 1474. ——­, oil of turpentine, 1452. ——­, positive, 1455, 1467, 1484. ——­, negative, 1468, 1472, 1484. ——­, ——­, of rapid recurrence, 1468, 1491. ——­, positive and negative in different gases, 1455, 1475, 1506.